Senior iOS Engineer

Citizen’s mission is to protect the world. We began by opening the NYC and San Francisco 911 system to local Citizen app users, creating access to real-time crime and safety information. By increasing situational awareness and transparency, we are making communities safer than ever before.

Since our launch, 3% of New Yorkers use our app every month, and that growth is accelerating. We launched San Francisco last fall, and over 1% has already joined the Citizen safety network. We send over 4 million crime notifications each month, alerting users to emergencies and dangerous situations near them. Citizen broke both recent NYC terror incidents to people nearby, keeping thousands in the vicinity safer and informed in real-time. Citizen has been featured on local NYC news over 100 times in the past 3 months.

We’re looking for passionate, mission-driven individuals to help take the Citizen app to the next level as we scale up new cities and expand globally.

Citizen is backed by Sequoia Capital and Founder’s Fund.

Our Challenges

Scaling: We have one of the fastest growing organic user bases in NYC and SF. Soon we will launch nationwide and we need to support that scale. A Citizen international launch will follow.

Bursting: Without warning, a major incident occurs and multiple users start live-streaming video. We notify our entire user base, causing a massive burst of simultaneously connected clients. The core systems we build need to efficiently support traffic that can grow to hundreds of thousands of concurrent users today, and millions in the future.

Analytics: We want to alert users to incidents that matter to them, in a way that scales across different geographic densities and demographics.